Now that you've been stretching you mind by geeking out, it's time to take the next step, and push your mind to the limits with puzzles!

I've tried to find a good variety of logic puzzles, to help keep your interest up. Some of these you can play until you solve, while others will keep challenging you as long as you care to keep playing them.

Collider: In this game, all you have to do is annihilate all the postive and negative balls by hitting them into each other. However, it can't be done directly. Instead, you usually have to use a Rube Goldberg-style approach to knock them out. This will have a familiar feel to those who've played The Incredible Machine.

Combination Lock: Just as the title suggests, the challenge is to open a combination lock as fast as you can. You're given clues as to the nature of the combination, and have to work it out from there.

Mahjongg Solitaire: If you've been using a computer for at least 5 years, I'm guessing you've played some version of this classic game. Simply remove the matching Mahjongg tiles that aren't blocked by any other tiles on any side or above it. You'll quickly remember how addicting this game is.

Mental Ladders: This is a series of puzzles I wrote up about 2 years ago. Mental Ladders are puzzles you have to work out 1 step at a time, working towards the goal of solving all the puzzles. Some of these are positively fiendish!

The instructions in this puzzle are in Japanese, so here they are in English:• The ferry can carry no more than 2 people.• Only the mother, the father and the policeman can operate the ferry.• The girls can't be left in the presence of the father without their mother.• The boys can't be left in the presence of the mother without their father.• The thief can't be left in the presence of any family member without the policeman.• Click on the people on shore to place them on the raft.• Click on the people on the raft to place them on shore.• Click on the red lever to send the raft across the river.

Sprout: All I can really say about Sprout is just click the link. Part of the challenge is figuring out the object of the game, after which you have to figure out how to achieve it. This game is not only great puzzle-wise, but style-wise, too.

TJ Wriggle Puzzles: You have to lead one or more worms to the exit, but you need to move them so that they're not blocked by their own heads and tails, or those of other worms. It sounds simple enough...

Were these puzzles not enough to sate your logic lust? Check out more puzzles at Plastelina and Smart-Kit.